Functionalisation of Lead Halide Perovskites with Anthracene

After only a decade’s worth of research and development, lead halide perovskites are set to become the basis of a new generation of cheap and highly efficient photovoltaic devices. However, traditional lead halide perovskites such as methylammonium lead triiodide or formamidinium lead triiodide suffer from an intolerance to moisture and high temperatures. 2D Ruddlesden-Popper lead halide perovskites and all inorganic caesium lead halide perovskites have gained attention in recent years due to their improved stability with respect to these environmental conditions. Like all solar cell technologies, simple lead halide perovskite solar cells have a theoretical maximum efficiency limit of around 30%. Coupling organic fluorophores to semiconducting nanomaterials is a potential route to circumventing and exceeding this efficiency limit. In this work attempts are made to couple anthracene functional groups to 2D Ruddlesden-Popper lead halides and caesium lead trihalide perovskites. The results of this study show that energy transfer does occur between anthracene and caesium lead trihalide nanocrystals, resulting in increased perovskite emission. These results show that organic fluorophores can be utilised in conjunction with perovskite semiconductors, opening up the possibility of circumventing efficiency limits for perovskite photovoltaic technologies.